When Prepping Avocados In Advance, Prevent Browning With One Simple Step

It's easy to love avocados for their creamy texture, vibrant green color, and spread-ability on everything from toast to tacos. Besides knowing how to pick the best avocados at the store, it's helpful to know how to keep them from turning brown after being cut. If you're prepping avocados ahead of time, keeping them fresh is a must.

To understand how to stop avocados from browning, it's helpful to know why it happens in the first place. Not to get super scientific, but like apples and bananas, avocados undergo a process called enzymatic browning when exposed to air. Once the flesh is cut and the surface is no longer protected by the skin, the enzymes in the fruit react with oxygen. This reaction causes the flesh to develop an unappetizing brown color.

Avocado that's turned brown isn't necessarily dangerous to eat, but it can't help but affect its appeal. It also signals oxidation, which negatively affects flavor and texture. Fortunately, there's a couple simple steps that make all the difference: add acid and cover tightly.

Acid slows down the browning reaction by decreasing the enzyme activity responsible for oxidation. Citrus fruits are the most common acid sources for this task, with lime and lemon juice being the most popular. That said, yuzu is another citrus you can use to keep your guac green. Not only are they acidic enough to be effective, but their flavor pairs naturally with avocado.

To add acid, just squeeze a small amount of citrus juice over the exposed surface. For mashed avocados or guacamole, you can mix the juice directly in. If you're making guacamole in advance, adding lime juice and a sprinkle of salt will help preserve the color and flavor for longer.

Once you've got the acid added, the next step is to minimize air exposure. Air is what allows the yucky browning reaction to occur, so reducing the avocado's contact with oxygen will help keep it green and gorgeous. The best approach is to cover the avocado directly with plastic wrap, pressing gently against the surface to eliminate any air pockets. For make-ahead guacamole, make sure store it in an airtight container and smooth the surface with a spoon. Just like a cut avocado, press some plastic wrap right against the top to keep out oxygen. 

One supposed trick you never want to use is storing your avocado in water. This social media "hack" is actually harmful because of all the bacteria potentially harboring on the skin. Soaking it in water creates the perfect breeding ground for germs which cause foodborne illness. You'll also want to avoid using a metal knife to cut avocados because the copper and iron found in these knives triggers the oxidation process. (Avocados are kind of high-maintenance.) With a little planning, you don't have to settle for sad, brown slices. When in doubt, citrus, cling wrap, and refrigeration are your best bet.